F. prausnitzii (ATCC 27766) or its supernatant can also exert protective effects by inhibiting Th17 differentiation and IL-17A secretion in both DSS-induced mouse colitis (Huang et al. 2016) and TNBS-induced colorectal colitis in rats (Zhang et al. 2014, 2019), and upregulating regulatory T cells (Qiu et al. 2013) and butyrate production to maintain Th17/Treg balance (Zhou et al. 2018a) in a colitis rat model and in vitro. The gene discussed is IL17A; the disease is colitis.